The present invention relates to an imaging apparatus having a rotary table to be used for monitoring and recording.
FIG. 9 is a block diagram showing the configuration of a conventional imaging apparatus. With reference to FIG. 9, n combinations of desired position data with respect to control items of four kinds 1(n) to 4(n) are stored in a preset unit 2. One arbitrary combination is selected according to an input supplied from a controller 41. A comparator 13 is supplied with selected desired position data of 1(n), such as 1(2). Its output is inputted to a horizontal-angle control motor 15 via a driving amplifier 14. Turning force of the motor 15 drives horizontal rotation of a rotary table via a reduction gear or the like. The horizontal angle of the rotary table is detected by a position sensor 16 and inputted to the comparator 13. A comparator 23 is supplied with desired position data, such as 2(2), of the preset unit 2. A vertical-angle control motor 25 drives vertical rotation of the rotary table. In addition, a series of operations of a driving amplifier 24, the motor 25, and a position sensor 26 are the same as those of the driving amplifier 14, the motor 15, and the position sensor 16. In completely the same way, numerals 33 and 43 denote comparators. The comparators 33 and 43 are supplied with desired position data 3(2) and 4(2), respectively. Numerals 34 and 44 denote driving amplifiers, and numerals 35 and 45 denote zoom-control motor and focus-control motor. The driving amplifier 34 and the motor 35 drive the zoom, whereas the driving amplifier 35 and the motor 45 drive the focus. Numerals 36 and 46 denote position sensors.
Operation of the conventional imaging apparatus having the above described configuration will now be described. Among one set of data selected by a movement instruction, desired position data of horizontal angle 1(2), desired position data of vertical angle 2(2), desired position data of zoom 3(2), and desired position data of focus 4(2) are inputted to the comparators 13, 23, 33 and 43, respectively. In the comparator 13, the desired position data 1(2) supplied from the preset unit 2 is compared with the output of the position sensor 16. An output proportionate to the difference between them is-amplified by the driving amplifier 14. The amplified output is supplied to the motor 15. The angle of the rotary table rotated horizontally by the rotation output of the motor 15 is converted into an electric signal by the position sensor 16. The electric signal is fed back to the comparator 13. If the horizontal angle has reached the desired position data value, the motor 15 is stopped. Operations of control items of three other kinds are also conducted in the same way.
In this way, the conventional imaging apparatus can move to respective desired values of various control items set beforehand and take a desired image according to a command given from the controller.
(1) In the above described conventional imaging apparatus, however, respective movement operations are conducted independently. Time values required for operations of respective control items depend upon initial values and desired values of positions and hence they are divergent. Thus the time required for a camera to yield a desired image is indefinite. Whether the movement has been completed and the desired image is ready to be displayed or not cannot be sensed by the controller 41. Therefore, the conventional imaging apparatus has a problem (a first subject) that the next movement may be started in response to the next movement instruction issued by the controller 41 although the preceding movement has not been completed and the desired image is not obtained. PA1 (2) Furthermore, in the above described conventional imaging apparatus, respective movement operations are conducted independently. Therefore, if a desired visual field has already been obtained before all control items arrive at desired values, it is wasteful to wait for the succeeding movement time, resulting in a second subject. PA1 (3) Furthermore, in the above described conventional imaging apparatus, time lengths required for movement from initial positions respectively of the horizontal angle and vertical angle of the rotary table to next desired positions are not equal, in general, between the horizontal rotation and vertical rotation. In case the vertical rotation, for example, is completed earlier, the imaging apparatus goes straight ahead obliquely in the direction of composition of the horizontal speed and the vertical speed during the vertical rotation whereas the imaging apparatus goes straight ahead in the horizontal direction after the vertical rotation has been completed. Therefore, the movement direction of the screen is bent. This results in a third subject that the observer feels a malaise. PA1 (4) Furthermore, in the above described conventional imaging apparatus, a plurality of sets of preset position data are executed to conduct movements in the order of preset number with respect to control items such as the horizontal angle and vertical angle of the rotary table. Therefore, direction of movement is random and many reciprocating movements are conducted in vain. This results in a fourth subject that the period of making one round among preset position data is long. PA1 (5) Furthermore, in the above described conventional imaging apparatus, subjects to be monitored during the daytime are different from subjects to be monitored during the night. This results in a fifth subject that desired position data preset for control must be changed over between daytime and night by means of a switch. PA1 (1) Means for solving the first subject in the imaging apparatus of the present invention includes control means for selecting one set out of a plurality of sets of desired position data preset for control and for causing operation, power sources provided for respective control items to cause movement toward desired positions, position sensors provided for respective control items to generate current position information, completion detectors provided for respective control items to detect movement completion, and an AND circuit for performing an AND function on outputs of all completion detectors. PA1 (2) Means for solving the second subject in the imaging apparatus of the present invention includes control means for selecting one set out of a plurality of sets of desired position data preset for control and for causing operation, power sources provided for respective control items to cause movement toward desired positions, position sensors provided for respective control items to generate current position information, completion detectors provided for respective control items to detect movement completion, and computing means for calculating a range of visual field of the imaging apparatus on the basis of outputs of all completion detectors and outputs of all position sensors. PA1 (3) Means for solving the third subject in the imaging apparatus of the present invention includes control means for selecting one set out of a plurality of sets of desired position data preset for control and for causing operation, with respect to control items of a horizontal angle and a vertical angle, driving means provided for respective control items to drive power sources, power sources provided for respective control items to cause movement toward desired positions, position sensors provided for respective control items to generate current position information, and computing means for calculating time values respectively required for horizontal movement and vertical movement on the basis of desired position data of respective control items and outputs of position sensors of respective control items, and for deriving such control outputs as to make shorter one of required time values equal to the other. PA1 (4) Means for solving the fourth subject in the imaging apparatus of the present invention includes control means for selecting such an execution sequence as to minimize a period of one round out of all combinations of execution sequences for a plurality of sets of desired position data preset for control by means of calculation, the control means storing the selected execution sequence and ordering execution in the execution sequence. PA1 (5) Means for solving the fifth subject in the imaging apparatus of the present invention includes provision of a function of discriminating control data by using specific data preset in addition to a control item or specific data included in data of the control item. PA1 (1) By the means for solving the first subject, movements toward desired positions are conducted with respect to respective control items after desired control values are given, and signals are yielded from the completion detectors. When all movements have been completed, the control means can receive an operation completion signal by the operation of the AND circuit. It is thus possible to realize an excellent imaging apparatus with rotary table which move toward desired positions after desired control values are given and which outputs an operation completion signal when all movement have been completed. PA1 (2) By the means for solving the second subject, the computing means calculates a desired visual field and a current visual field on the basis of desired control values and outputs of the position sensors, and compares the desired visual field with the current visual field. Even if movements to desired positions are not completed with respect to respective control items after desired control values have been given, the control means can receive an operation completion signal when the desired visual field has been obtained in the imaging apparatus, resulting in time saving. It is thus possible to realize an excellent imaging apparatus with rotary table which outputs an operation completion signal when the desired visual field has been obtained even if the desired control position is not reached. PA1 (3) By the means for solving the third subject, the computing means calculates time values required for movements respectively of horizontal angle and vertical angle on the basis of desired position data and current position information, and compares them. The computing means controls the driving means so as to prolong shorter one of required time values and make it equal to longer one. Since movements of horizontal angle and vertical angle are thereby completed at the same time, the imaging apparatus moves on a straight line. Thus, image movement does not provide feeling of a malaise. It is thus possible to realize an excellent imaging apparatus with rotary table in which the horizontal angle and horizontal angle simultaneously arrive at desired control positions. PA1 (4) By the means for solving the fourth subject, the control means calculates the period of one round of execution for all combinations of sequences of as many desired control position data as been preset, compares them with each other, derives and stores a combination having the shortest period, and orders execution in that sequence. By only presetting various position data needing images, therefore, movements are executed in such a sequence that one round of them can be conducted automatically in the shortest time. That is to say, it is possible to realize an excellent imaging apparatus with rotary table which can move to conduct one round among preset subjects in a short time. PA1 (5) By the means for solving the fifth subject, the control means can extract, discriminate and control a specific item out of preset data. Therefore, it is possible to realize an excellent imaging apparatus with rotary table which can automatically select a data group.